Process for treating sweet-gum woods and the like



April 1934- T. H. SAMPSON 1,953,193

PRUCESS FOR TREATING SWEET GUM WOODS AND THE LIKE Filed May 13, 1930 INVENTOR 77 50221 :25 fiQzr/ozmfkmpa 07:,

BY Mai ATTORN EY Patented Apr. 3, 1934 UNITED STATES PATENT OFFICE stain, stick-rot,

prevented.

A further object of my invention is to so carry out said process thata deep red permanent color will be imparted to both the sap and heart wood of the tree growth.

A still further object provide an apparatus that will accomplish this result in a most eificient, simple and inexpensive manner.

This invention is designed as an improvement over the process and apparatus disclosed in my Patent No. 1,048,102 dated December 24, 1912 for Process for treating red-gum and other like woods.

As set forth in lines 27 to 50 inclusive, of page 3 of the above mentioned patent and as found by subsequent use of the process and apparatus disclosed in said patent the wood treated by the means of the patent was not satisfactory unless the same had been soaked in water before the It is, therefore a further and very important object of my invention to provide a process and apparatus of the type described which does not require soaking of the wood in water as a preliminary step in the process for obtaining successful results and which besides being an improvement on the original process is,- therefore, especially adapted also for efiicient use in inland lumbering operations.

treatment.

A still further object sweet gum wood.

Other objects and advantages of the process and the apparatus for carrying the same into operation will appear as the specification proceeds and the invention will be more particularly defined in the appended claims.

Proceeding to the detail description of the invention, the apparatus is illustrated in the accompanying drawing, forming a part of the application, in which Figure 1 is an elevational view of the appara-.

tus set up for operation.

PROCESS FOR TREATING SWEET-GUM WOODS AND THE LIKE Thomas Harlow Sampson, Helena, Ark.; Whitney Trust & Savings Bank and William C. Ermon, executors of said Thomas Harlow Sampson, deceased, assignors to Susan Crane Ermon Sampson Application May 13, 1930, Serial No. 451,971

4 Claims. (CI. 99-12) Figure 2 is a fragmentary elevational detail view of a portion of the device, and

Figure 3 is a detail plan view of a portion of the apparatus.

In carrying out the invention I provide a suitable chamber 1 which may be constructed in any desired form, of any desired material, of any desired size and in any desired manner provided it is air tight and adapted for the retention of fluids under pressure. In the embodiment shown, this chamber 1 is constructed of a plurality of cylindrically-formed sections 2 having a slight taper extending from end to end to permit telescoping of said sections in fluid tight relationship. These sections may be; welded, riveted or secured together in any other suitable fashion. A cap 3 covers one end of the chamber.

At the opposite end of this chamber 1 is a gate 4 swingably mounted on pivots 5 and adapt-v ed to seal the opening 6 at the end of chamber 1 against fluid pressure, when in closed position,

' by any preferred means, not shown, but which might conveniently be engaged through the slots 7 and cooperating slots 8 in the end section; of chamber 1 and gate 4, respectively. The end cap 3, may also be constructed similar to gate 4 for passage of a charge in and out of chambers. It is in this chamber that the steaming of the checking,

of the invention is to signed to withstand the fluid pressure occasioned during the steaming operation.

Within the chamber 1 and secured to the inner surface thereof are a series of brackets 9 and 10 designated to mount thereon the rails 11 and 12, respectively, of a railroad track. This railroad track is adapted to receive the wheels 13 of the car 14 which passes thereover and which is designed to carry the wood into and out of the chamber 1 for the treatment.

It will be noted that there are secured between the brackets 9 and 10, a pair of pipes 15 and 16 which as shown most clearly in Figure 3 have a. plurality of apertures 17 extending therealong. These pipes are provided for the purpose of the admission of steam and air, both of which are required at certain times of the process, to the chamber 1 and the apertures 17 in the pipes are adapted to direct this steam or air under and up of my invention is to the above mentioned patent I made use of superheated steam, requiring in addition to these pipes 15 and 16, a series of steam pipes upon which the i V steam from the aperture 17 impinged and was,

wood takes place and the chamber is thus deelevated in temperature. In my present process, however, the use of super-heated steam being harmful, it is not used and the steam apparatus illustrated is all that is required.

For the admission of steam to the pipes 15 and 16 which must have their ends closed, I provide the steam pipe 18 having a branch19 for connection to any suitable source of steam supply, not shown, and a branch 20 having a valve 21 thereon to provide for the admission of air from the atmosphere when a vacuum is forming within the chamber 1. The most accessible portion of branch 19 may also be provided with a valve, for example, the one shown at 23 for the control of the admission of steam.

It will be noted that the chamber 1 is mounted in a sloping fashion by means of the standards 24. This is done to allow withdrawal of the black or brown flocculent matter consisting of the sap associated with the steam from the lowest portion 25 of said chamber 1 through the pipe 26 and into the sap or drainage tank 27 having a cook 28 thereon for withdrawal of said flocculent matter.

The pipes controlling the admission of steam and air and-controlling the exhaust of flocculent matter may be provided with suitable valves for manual control thereof, if desired. Suitable gauges, such as that illustrated at 29 for the indication of temperatures, pressures, liquid contents or for other purposes may also be provided for the use of the operator.

It is thus seen that the apparatus comprises a car or cars for carrying the wood into a fluidtight pressure chamber having rails for the passage of said car or cars and pipes for the admission of steam, air and heat therein, and means for exhausting the flocculent matter containing the sap therefrom.

In treating the sweet gum woods, such as the sap and heart wood of the red gum to prevent warping, twisting, hollow-homing, stick-rot, checking and other deteriorating effects and to give said woods a uniform deep permanent red color throughout, doing away with the necessity of staining and other treatments, I cut the wood into the desired form, such as lumber, or leave it in its original form and mount the same on the car or cars 14.

The car or carsare then runinto the chamber over the tracks 11 and 12 and the end or ends of said chamber sealed against fluid pressure by means of the gate 4, or together with a similar gate at end 3.

Steam is then lead into the cylinder from the perforated pipes 15 and 16 slowly saturating the cylinder air and the lumber or wood at a temperature below 212 Fahrenheit. This application of steam is continued until the condensed black gummy matter containing the sap from admitted to the chamber 1 until a pressure of twenty pounds per square inch of steam is con- This takes from six to During these operations the cock tained in the cylinder. eight hours.

28 is-closed.

At this state of the procedure, the steam from perforated pipes 15 and 16 is shut off and the cock 28 is opened to a small extent, 1. e., just sufficiently to let the condensed liquids pass out, thereby bringing about a gradual reduction in the pressure exerted by the fluids in chamber 1 and a loss in temperature of the entire chamber and contents. This slow cooling, drying and loss of pressure is a most important feature of my invention as it prevents the rapid loss of heat from the surfaces of the wood being worked upon with consequent prevention of the usual checking and hollow-horning in the heart or center of the wood as in ordinary processes of this nature.

When the pressure of the chamber 1 reaches zero or atmospheric pressure and the temperature is 212 Fahrenheit, a vacuum begins to form. At this time the operator admits atmospheric air through the valve 18 and through the apertures 1'7 of the pipes 15 and 16. The introduction of the air through the entire length of the perforated pipes slowly and evenly enters the chamber and cools the contents thereof until the cylinder is filled with air instead of steam, which air is cooled to the same temperature as the outside atmosphere, thereby making it feasible to open the cylinder doors for releasing the charge. This step in the process takes from five to seven hours time. The introduction of this air slowly and evenly throughout the entire length of the chamber is a very important step in the process as when the air is introduced at one point through one large opening as usual in processes of this kind, checking and hollow-homing and other forms of warping of the wood take place, immediately because of the too rapid cooling and drying of the surfaces.

The charge is then released from the chamber and the-wood is carried by the car into a narrow shed, not shown, which may be of any suitable construction, but which preferably should be of a slightlygreater size than the charge and associated car. If it is not feasible to provide a shed, the charge must be covered with a cloth immediately after release from the chamber. The wood is then permitted to cool and dry until heat ceases to be given off.

After this cooling process, being then but partly dried, the wood may be carried by the car to most intense change in the nature of the gummy This material contents of the wood occur. changes from a sweet gum to one so acid as to rapidly combine with and corrode the inside of a chamber shell, the car, the tracks, piping etc. It is, therefore, necessary to treat these parts immediately after the withdrawal of the charge with a light paraiiine mineral oil which may be sprayed within the chamber by any suitable means, not shown. It will be found that the chamber walls and the other metal materials within the chamber sprayed in this fashion or otherwise coated with the mineral oil will not corrode or rust.

It will also be found that a gum Wood treated, cooled and dried as outlined above will not deteriorate in the fashion in which woods dried in an ordinary manner deteriorate and that both sap and heart gum wood so treated will have a deep permanent red color extending uniformly throughout the wood from the surface to the heart or center thereof.

It will still further be observed that this deep red color will not fade as in Woods treated by.

ordinary means and that sap-stain and mould will not occur, because of the removal or chemical change in the nature of all the sap.

Is is thus seen that I have provided a process and apparatus for the treatment of sweet gum. woods and more particularly red gum woods and. the like, that is especially adapted for use in. inland lumbering operations, wherein the lack of water prohibits a soaking operation prelimi-- nary to the sap removing process.

What is claimed is:-

1. A process for treating sweet gum woods and. the like, consisting in steaming the Wood at at-- mospheric pressure until the black sap ceases torun therefrom, and becomes a clear and brownish. liquid in color, steaming under pressure until its: moisture contents is chemically changed by the steam action and is driven from the wood, slow-- ly reducing the pressure, gradually immersing the wood in atmospheric air until the temperature has been reduced to that of the atmosphere, and slowly further cooling and drying said wood in a confined space.

2. A process for treating sweet gum woods and the like, consisting in steaming the wood at atmospheric pressure and at a temperature below 212 Fahrenheit from sixteen to twenty hours, further steaming the wood under increased pressure and increased temperature fora period of six to eight hours, slowly reducing the pressure to atmospheric and the temperature to 212 Fahrenheit, gradually immersing the wood in atmospheric air until the temperature has been pressure to twenty pounds, reducing said pres- I sure to atmospheric pressure and said temperature to 212 Fahrenheit or below by gradually releasing the distillates from said chamber, slow- 1y immersing said wood in air by introducing atmospheric air to said chamber until the interior of the chamber is at atmospheric temperature and slowly cooling and drying said wood in a confined space.

4. The herein described steps in a process of treating sweet gum woods and the like, which consists in first steaming the wood in a confined space at atmospheric pressure to drive out certain liquid constituents thereof, increasing'the steam pressure when the liquid constituents cease to flow to thoroughly saturate the wood, reducing the steam pressure to atmospheric pressure and the temperature by gradually releasing the distillates from the confined space, slowly admitting atmospheric air to the wood within the confined space until the steam has been entirely displaced and the wood entirely immersed in atmospheric air, and the temperature has been reduced to that of the atmospheric air and then removing the wood into the atmosphere for subsequent treatment.

THOMAS HARLOW SAMPSON. 

